<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
		<script>
			var quarter=parseInt(prompt("请输入一个月份"));
			if(quarter>=2&&quarter<=4){
				alert("第一季度");
			}else if(quarter>=5&&quarter<=7){
				alert("第二季度");
			}else if(quarter>=8&&quarter<=10){
				alert("第三季度");
			}else if(quarter==1||quarter==11||quarter==12){
				alert("第四季度");
			}else{
				alert("请输入正确的月份!");
			}
		</script>
	</body>
</html>
